Electrostatic field-assisted low-temperature preservation is considered a novel technology, which provides an effective means of extending the shelf-life of meat. This study aimed to investigate the ...effects of different output time modes of a high voltage electrostatic field (HVEF) on the water holding capacity (WHC) of chilled fresh pork during controlled freezing-point storage. Under a direct current HVEF generator, chilled fresh pork samples were treated by the single, interval, or continuous HVEF treatment, with a control check group receiving no HVEF treatment. It was determined that the WHC of the continuous HVEF treatment higher than the control check group. This difference was proven by analyzing the moisture content, storage loss, centrifugal loss, cooking loss, and nuclear magnetic resonance imaging. Furthermore, the mechanism behind HVEF-assisted controlled freezing-point storage reduced the moisture loss was conducted by examining the changes in the hydration characteristics of myofibrillar protein. The study revealed that myofibrillar proteins exhibit high solubility and low surface hydrophobicity under continuous HVEF. Additionally, continuous HVEF has been demonstrated to effectively maintain the higher WHC and lower hardness of myofibrillar protein gel by inhibiting the water molecule migration. The demonstration of these results showcases the effectiveness of electrostatic fields for the future physical preservation of meat.
•The electrostatic field-assisted controlled freezing-point storage improved the WHC of chilled fresh meat.•Changes in myofibrillar protein hydration properties may affect the WHC of chilled fresh meat.•The use of continuous and interval electrostatic fields can improve the WHC of chilled fresh meat.
Foods have been commercially frozen for over 140 years. While improper frozen storage often causes food quality loss, the frozen damage induced by ice crystal growth is a serious problem. Freezing ...point (FP) regulation that promotes and inhibits ice nucleation, and controls ice crystal growth and recrystallization, may alleviate this problem. Some naturally sourced biosubstances with eco-friendly, green, nontoxic and highly effective characteristics are verified to regulate FP, showing potential for application in foods and food-related areas.
This review introduces three groups of FP-regulating biosubstances, including ice-nucleating proteins (INPs), anti-freezing proteins (AFPs) and natural deep eutectic solvents (NADES). Existing knowledge of these biosubstances and updated information concerning their mechanisms for regulating FP are summarized. In addition, current applications of these natural FP regulators in foods or in food-related areas are presented, involving food processing, packaging and transgenic foods. Future applications of these biosubstances in the food and food-related researches are briefly discussed.
The effect of natural FP regulators in improving food quality is worthy of further investigation into more extensive food applications, especially for INPs and NADES. The current review indicates that natural FP regulating biosubstances reveal application potential in foods and food-related areas. Future studies should mainly focus on bio-based or bio-inspired anti-freezing, micro/none ice-based cold storage and energy conservation in the food and food-related researches.
•Ice-nucleating proteins effectively elevate freezing points.•Anti-freezing proteins and natural deep eutectic solvents reduce freezing points.•Ice-binding proteins regulate freezing points through special function domains.•Natural freezing point regulators can be applied in the food industry.•This is an updated review on natural freezing point regulators in food area.
•The physical properties of the bio-jet fuel can be adjusted by controlling the CC coupling conditions.•The alkane with spiro ring structure has the low freezing point.•W/O microemulsion formed by ...the NaOH solution and cyclohexane favors the aldol condensation.•The density of the jet fuel is 0.869 g·ml−1 and the freezing point is lower than −60℃.
Production of jet fuel with high performance is attractive in the field of biomass utilization. This paper provides a way to controllably produce renewable jet fuel with high-density and low-freezing point by the condensation of biomass-derived cyclopentanone and followed hydrodeoxygenation. It is found that the freezing point of the jet fuel decreased rapidly with the increase of the content of spirocyclic alkane and the density increased gradually with content of tricyclic alkane. And the composition of jet fuel can be adjusted by controlling the reaction conditions of cyclopentanone condensation. At 30 °C and 3 h, the precursors of jet fuel were prepared by condensation of cyclopentanone over NaOH catalyst and the final obtained HDO products were comprised of 54.56% bicyclopentane, 31.88% tricyclic alkane and 13.56% spirocyclic alkane. The density of the jet fuel was 0.869 g·ml−1 and the freezing point was less than −60 °C. These parameters are obviously superior to that of commercial Jet-A.
The NOAA/NESDIS/NCEI Daily Optimum Interpolation Sea Surface Temperature (SST), version 2.0, dataset (DOISST v2.0) is a blend of in situ ship and buoy SSTs with satellite SSTs derived from the ...Advanced Very High Resolution Radiometer (AVHRR). DOISST v2.0 exhibited a cold bias in the Indian, South Pacific, and South Atlantic Oceans that is due to a lack of ingested drifting-buoy SSTs in the system, which resulted from a gradual data format change from the traditional alphanumeric codes (TAC) to the binary universal form for the representation of meteorological data (BUFR). The cold bias against Argo was about −0.14°C on global average and −0.28°C in the Indian Ocean from January 2016 to August 2019. We explored the reasons for these cold biases through six progressive experiments. These experiments showed that the cold biases can be effectively reduced by adjusting ship SSTs with available buoy SSTs, using the latest available ICOADS R3.0.2 derived from merging BUFR and TAC, as well as by including Argo observations above 5-m depth. The impact of using the satellite MetOp-B instead of NOAA-19 was notable for high-latitude oceans but small on global average, since their biases are adjusted using in situ SSTs. In addition, the warm SSTs in the Arctic were improved by applying a freezing point instead of regressed ice-SST proxy. This paper describes an upgraded version, DOISST v2.1, which addresses biases in v2.0. Overall, by updating v2.0 to v2.1, the biases are reduced to −0.07° and −0.14°C in the global ocean and Indian Ocean, respectively, when compared with independent Argo observations and are reduced to −0.04° and −0.08°C in the global ocean and Indian Ocean, respectively, when compared with dependent Argo observations. The difference against the Group for High Resolution SST (GHRSST) Multiproduct Ensemble (GMPE) product is reduced from −0.09° to −0.01°C in the global oceans and from −0.20° to −0.04°C in the Indian Ocean.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Controlled freezing point storage assisted by the electrostatic field has been proven to maintain the quality of fresh meat effectively. In this study, we evaluated the freshness variation of pork ...under controlled freezing point storage assisted by different high-voltage electrostatic field (HVEF) usage frequencies, including single-used HVEF (SHVEF), interval-used HVEF (IHVEF), and continuous-used HVEF (CHVEF). The pH value, total volatile basic nitrogen (TVB-N), total viable count (TVC), and bacterial community composition were determined. The results showed that the pH value in the three groups gradually decreased, while the TVB-N and TVC increased along with the growth of bacteria. The IHVEF and CHVEF treatments effectively delayed the decrease in pH value and significantly reduced the overall level of TVC and TVB-N in fresh pork at a later storage period. Bacterial community composition analysis showed that the dominant bacteria in all three treatments were
Pseudomonas
,
Latilactobacillus
, and
Brochothrix
, and HVEF treatment can significantly decrease their diversity and abundance. The functional analysis showed that HVEF treatment has influenced the pathways of amino acid metabolism, carbohydrate metabolism, and energy metabolism during controlled freezing point storage. In conclusion, the HVEF treatment has a significant (
p
< 0.05) inhibitory effect against dominant bacteria and enhanced the storage quality of fresh pork. These results could provide theoretical guidance for the possible application of HVEF technology in controlled freezing point preservation of meat.
Aqueous zinc-based energy storage (ZES) devices are promising candidates for portable and grid-scale applications owing to their intrinsically high safety, low cost, and high theoretical energy ...density. However, the conventional aqueous electrolytes are not capable of working at low temperature. Here we report a frigostable, cost-effective, safe and eco-friendly hybrid electrolyte with high zinc-ion conductivity (6.9 mS cm
−1
at −40 °C), and high reversibility of Zn plating/stripping, which consists of water, ethylene glycol (EG) and zinc sulfate salt (ZnSO
4
). Experiments together with theoretical calculations demonstrated that the unique solvation interaction of Zn
2+
with EG can effectively enhance the hydrogen bonding between EG and H
2
O and weaken the solvation interaction of Zn
2+
with H
2
O, thus providing the hybrid electrolyte with a lower freezing point and reversible Zn/Zn
2+
chemistry. As a proof-of-concept, both Zn-ion hybrid supercapacitors (ZHSCs) and Zn-ion batteries (ZIBs) with the hybrid electrolytes delivered high energy densities (36 W h kg
−1
for the ZHSC and 121 W h kg
−1
for the ZIB), high power densities (3.1 kW kg
−1
for the ZHSC and 1.7 kW kg
−1
for the ZIB) and long-cycle life (5500 cycles over 110 days for the ZHSC and 250 cycles for the ZIB) at −20 °C. This work provides a new option for low-temperature energy storage devices.
A frigostable aqueous hybrid electrolyte enabled by the solvation interaction of Zn
2+
-EG is proposed for low-temperature zinc-based energy storage devices.
The absence of electrical resistance exhibited by superconducting materials would have enormous potential for applications if it existed at ambient temperature and pressure conditions. Despite ...decades of intense research efforts, such a state has yet to be realized
. At ambient pressures, cuprates are the material class exhibiting superconductivity to the highest critical superconducting transition temperatures (T
), up to about 133 K (refs.
). Over the past decade, high-pressure 'chemical precompression'
of hydrogen-dominant alloys has led the search for high-temperature superconductivity, with demonstrated T
approaching the freezing point of water in binary hydrides at megabar pressures
. Ternary hydrogen-rich compounds, such as carbonaceous sulfur hydride, offer an even larger chemical space to potentially improve the properties of superconducting hydrides
. Here we report evidence of superconductivity on a nitrogen-doped lutetium hydride with a maximum T
of 294 K at 10 kbar, that is, superconductivity at room temperature and near-ambient pressures. The compound was synthesized under high-pressure high-temperature conditions and then-after full recoverability-its material and superconducting properties were examined along compression pathways. These include temperature-dependent resistance with and without an applied magnetic field, the magnetization (M) versus magnetic field (H) curve, a.c. and d.c. magnetic susceptibility, as well as heat-capacity measurements. X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and theoretical simulations provide some insight into the stoichiometry of the synthesized material. Nevertheless, further experiments and simulations are needed to determine the exact stoichiometry of hydrogen and nitrogen, and their respective atomistic positions, in a greater effort to further understand the superconducting state of the material.
Aqueous Batteries Operated at −50 °C Nian, Qingshun; Wang, Jiayue; Liu, Shuang ...
Angewandte Chemie International Edition,
November 18, 2019, Letnik:
58, Številka:
47
Journal Article
Recenzirano
Insufficient ionic conductivity and freezing of the electrolyte are considered the main problems for electrochemical energy storage at low temperatures (low T). Here, an electrolyte with a freezing ...point lower than −130 °C is developed by using dimethyl sulfoxide (DMSO) as an additive with molar fraction of 0.3 to an aqueous solution of 2 m NaClO4 (2M‐0.3 electrolyte). The 2M‐0.3 electrolyte exhibits sufficient ionic conductivity of 0.11 mS cm−1 at −50 °C. The combination of spectroscopic investigations and molecular dynamics (MD) simulations reveal that hydrogen bonds are stably formed between DMSO and water molecules, facilitating the operation of the electrolyte at ultra‐low T. Using DMSO as the electrolyte additive, the aqueous rechargeable alkali‐ion batteries (AABs) can work well even at −50 °C. This work provides a simple and effective strategy to develop low T AABs.
Ice‐cold: An aqueous electrolyte with ultra‐low freezing point is designed by using dimethyl sulfoxide (DMSO) as an additive. Aqueous alkali‐ion (Li+, Na+, and K+) rechargeable batteries (AABs) assembled using this electrolyte can be operated at an ultra‐low temperature of −50 °C and retain ≈60 % of the capacity at 25 °C.
One of unsolved puzzles about water lies in how ion-water interplay affects its freezing point. Here, we report the direct link between tetrahedral entropy and the freezing behavior of water in Zn
...-based electrolytes by analyzing experimental spectra and molecular simulation results. A higher tetrahedral entropy leads to lower freezing point, and the freezing temperature is directly related to the entropy value. By tailoring the entropy of water using different anions, we develop an ultralow temperature aqueous polyaniline| |Zn battery that exhibits a high capacity (74.17 mAh g
) at 1 A g
and -80 °C with ~85% capacity retention after 1200 cycles due to the high electrolyte ionic conductivity (1.12 mS cm
). Moreover, an improved cycling life is achieved with ~100% capacity retention after 5000 cycles at -70 °C. The fabricated battery delivers appreciably enhanced performance in terms of frost resistance and stability. This work serves to provide guidance for the design of ultralow temperature aqueous batteries by precisely tuning the water structure within electrolytes.
To improve the stratum mechanical properties and prevent the geological disaster, we present a new approach by executing CH4 hydrate exploitation and CO2 sequestration below the freezing point of ...water to maintain the stratum stiffness during and after hydrate exploitation. An experimental method to clearly show the evolution of the stratum mechanical properties was built and a series of experiments were conducted to simulate the CH4 exploitation and CO2 sequestration process below and above the freezing point of water. The stratum stiffness was found to be maintained during the whole hydrate exploitation process when below the freezing point. Moreover, the presence of ice improves the stratum stiffness due to cementing the sandy grain. The CO2 injection into the hydrate-bearing sediments would further enhance the mechanical properties and realize a CO2 geological sequestration. Compared with hydrate exploitation above the freezing point, the CH4 recovery efficiency is a little lower when under below the freezing point and it decreased with the increased hydrate saturation due to the CH4 hydrate being surrounded by the generation of ice from hydrate dissociation. This phenomenon could be modified by injecting CO2, from which the CH4 recovery efficiency obviously improved for hydrate exploitation below the freezing point.
•Stratum stiffness was maintained during the hydrate exploitation when below 273 K.•The presence of ice improves the stratum stiffness due to cementing the sandy grain.•CO2 injection enhances the mechanical properties and realizes CO2 sequestration.•CH4 recovery efficiency was improved when below 273 K by injecting CO2.
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